Opinion: show flats for residential developments don't just tell us about a developer's dream demographic – they have the potential to turn a sales fantasy into part of the city's built fabric, says Sam Jacob.

I've often fantasised about writing a novel (well, novella maybe) about show apartments. A story about a show life in a show apartment where scripted domesticity is performed day and night like a Roxy Music song that was never quite written.

An artificial lifestyle staged for a voyeristic audience seems the perfect scenario to explore a very 21st century idea of the city. In all their synthetic domesticity show apartments distill a visible essence of something that's so pervasive yet hard to pin down: the way in which the market, marketing and architecture converge to reinvent the idea of the city.

To misquote Frank Lloyd Wright:
"Watch the little show flat... The new city is all around us in the haphazard making, the apparent forces to the contrary notwithstanding. All about us and no plan. The old order is breaking up."

Maybe this is what out of work actors do when they can't get a break

There's one down by Tate Modern for the Neo Bankside development that's been there (it seems at least) since the original Shakespearian Globe. The neo-flat rises above a hoarded compound, glazed to the world like a shopfront, its interior domesticity on display like a Dan Graham project from the 1970s.

Hang around at night when the interior lights go on and you can peer in. You'll see a figure in there opening and closing kitchen cupboards, going about what seems to be a life. Who knows if there's anything in those cupboards, if the appliances are even wired in. From our voyeristic distance it's easy to imagine this as a life lived as a performance to the world. Maybe it is even a real 21st century job, being paid to live according to particular scripts. Maybe this is what out of work actors do these days when they can't get a break.

Over in another show flat for another (not quite so high-end) development. You approach through a parking lot where an arrow with "sales" written on the tarmac like a highway directive points the way. Nowhere to park a bike, interestingly (obviously a demographic they aren't interested in courting). There's a garden laid out behind a fence full of tortuous topiary, large abstract chromed shape-ornaments.

Poplar seen through a Ralph Lauren eye

The sales suite itself is a prefab building with the charm of a miniaturised car showroom. It's decked out with themed paraphernalia. This one's theme is 'boating' – it is by a canal, you see, but why the boating that's foregrounded here is more rowing eights and cox-less fours is another question. There are photos of young chaps in boating blazers relaxing in the nearby park. It's Poplar seen through a Ralph Lauren eye. You can feel the sheer effort in working to engender a sense of aspiration that would play to a global market.

This is even more visible when you watch the video playing on a giant screen. Images of Big Ben, Trafalgar Square and a Black Cab flash up interspersed with stats telling you that its 15 minutes from Tate Modern, the Southbank and so on like an American sitcom special when for no apparent reason they come to London, ride up and down the Mall in a routemaster bus and bump into the Queen.

The sales pitch, in other words, obscures the idea of place, erases the idea of London as a real city. Invoking this glossy cliche as context only serves to suggest that the development is an isolated island, disconnected from the very ground it sits on, floating instead in a weightless miasma of empty signs, as though the contents of a souvenir shop had not only gained consciousness but that that consciousness had rebuilt a version of London based on its own DNA.

It feels strangely like something awful has happened

I'm greeted by a sales advisor who replies "people like you" when I ask who is buying. "Young, professional." Obviously lacking in character assessment. But I guess I know what she's trying to suggest: that here I might find a self-selecting ghetto of other me's that would like the things I like, do the things I do, share the values that I hold dear. In other words, community as a hall of mirrors.

Opening a door that could be a store cupboard you step into the actual fake apartment, a dislocated fragment of bad planning. The compressed lobby opens one way into a kitchen living room where there's a cookbook open on the counter – Italian – and a bottle of red too. In the bedroom on the bedside table, next to a pair of cufflinks, there is a framed photo a young couple having a great time on an exotic holiday. A necklace is coiled in a shell on the window sill.

It feels like we're poking around in the intimate domesticity of this fictitious couple – that we're cast as burglars or crime scene detectives. It feels strangely like something awful has happened.

Every building is both a building and a model of a way of life

This replica apartment is a microcosm of what's happening in the thing it refers to – the building that's going up next door that will have the real apartments, the real versions of that couple, the community of me's that will eventually live there. The development in other words is a fiction too. The narratives of young professionalness, of London-as-global-destination, its Ralph Lauren-ness are embedded in it. These fictions are made real, built into the actual fabric of the city.

All architecture does this. Every building is both a building and a model of a way of life. But it's a question of how this can be used productively. The depressing thing about this scenario is its narrowness of vision, its cliched, stagnant idea of what life might be.

Around the corner there is a very different example of how the show apartment can productively engage with the city. The Lansbury Estate was built as a real place to live. But it was also built as an explicitly public model of new ways of living. It was part of the 1951 Festival of Britain and formed the living core of an exhibition about how Britain would reinvent its built environment.

The debate about planning was carried out in a really public way

Amongst the real homes were pavilions and exhibits. These included the fabulous Gremlin Grange, a mock up of an old house designed with deliberate defects leaky pipes, creaking doors and cracked walls. Others included the Building Research Pavilion, showing in contrast to Gremlin Grange modern principles of construction. A red and white striped Town Planning Pavilion housed a model of a fictional new town, Avoncaster. Finally, visitors saw the real Lansbury, the embodiment of the ideas they'd just experienced.

The Lansbury and the amazing poster produced to publicise it titled New Homes Rise From London's Ruins by Abraham Games, is part of the show I'm co-curating for the British Pavilion at the Venice Biennale titled A Clockwork Jerusalem. It's a show that explores the ambitions and culture of post-war British architecture and planning. Part of the story is how much of the debate about planning was carried out in a really public way – through advertisements, exhibitions, posters, films and books. Marketing, in other words, was intrinsic to the idealistic ambitions of the period – from the brochures promoting the early Garden Cities to the Red Balloon TV commercial for Milton Keynes. Marketing and communications were necessary to help make real the worlds that planning proposed.

Marketing, architecture and development can be an incredibly powerful combination when they deploy integrity, imagination, intelligence and ambition.

Reno Nevada is struggling with this concept. Here in Reno, our brand has been tarnished by popular media (Reno 911), rundown casinos and a struggling economy. Yet, there are these oases of progressive architecture, like the Nevada Museum of art, which seem to have healing effect on the city.

Like-minded businesses are attracted to these buildings. They build around them and slowly change the neighbourhood. I could see Reno correcting its brand within the next five to ten years if they take these ideas to heart.